The present invention relates to air seeders and, in particular, to a diffuser for reducing air pressure at the distribution point of an air seeder to substantially zero to gravitationally deposit seed at a uniform preset soil depth and seed spacing.
A wide variety of agricultural seeders have been developed for planting seeds in prepared soil. A common seeder type found at relatively large farm operations is known as an “air drill” or “air seeder”. Multiple openers (i.e. planting/fertilizing arms) are typically mounted to a tractor-towed framework. The openers are commonly supported at preferred row spacings to wings or arms that span multiple rows. The wings collapse (e.g. fold upward) to permit travel over roads and deploy from a collapsed travel condition to span the intended row spacing.
Each seeder typically provides an opener head or “seed boot arm” assembly to open and control the depth of each opened furrow. Associated controls and assemblies are included to clean each furrow (e.g. scraper member), tamp the planted seed (e.g. seed firming wheel), and close the furrow (e.g. packer wheel). The seed is dispensed from a covered hopper and an associated fan powered air distribution assembly. The seed is directed from the hopper, sorted and directed via appropriate conduits and tubing to individual distribution ports at relatively high pressures to dispense individual seeds in the prepared furrows.
A problem common to air seeders is that of delivering the seeds at relatively high air pressures and high velocities that cause the seeds to bounce in or around the furrows and/or out of the furrows and consequently produce inconsistent seed placement and germination. The seeds during delivery to the seed boot may also be damaged such that cracked or split seed may not successfully germinate.
One solution to the problem of which applicant is aware is promoted under the name “D-Cup Diffuser”. The diffuser provides a conical housing having an internal spiral passageway that tapers from a large diameter input port to a narrowed diameter outlet port. Air borne seed is tangentially directed into the passageway at the input port. The conveying air is dissipated to the atmosphere at the input end of the diffuser. The seed is directed down through the spiral passageway and falls from the outlet port. The air pressure is dissipated until the seed falls only under the force of gravity.
A problem persists if the seed boot plugs with mud, debris or other matter during difficult planting times as the seeds then tend to follow the air stream and blow out the top of the device and producing skips in the planted field. Even though seed hose monitoring devices exist that alert an operator to a plugged delivery line, the operator typically is not alerted with sufficient lead time to correct the plugged condition since seeds are still flowing through the air/seed hose. Instead of being deposited into the furrow, the seeds are broadcast onto the top of the soil.
The present invention was developed to provide an alternative air diffusion assembly to gravity dispense seed from an air seeder. The diffuser includes a formed, resiliently mounted first valve piece in a tubular housing to reduce initial seed velocity. The seed deflects from the first valve piece to strike an associated second resiliently mounted valve piece. A screen fitted into a bore of the housing supports and cooperates with the first valve piece to produce multiple deflections of the seed between the valve pieces as air pressure is bled off. The first valve piece is mounted to pivot from the screen member and includes counter weight and deflection arm portions. Ultimately, the seed falls under the influence of gravity through a dispensing port.
A projecting flange or ledge piece exhibiting a half-moon shape adjacent the dispensing port momentarily collects the spent seed. The spent seed tends to fall from the flange at a relatively uniform, generally singulated rate into a prepared furrow with a spacing determined by the operating ground speed of the dispensing port. The seed particularly falls into a prepared furrow at a predetermined depth optimal to the growth of the particular seed.
The relative displacement between seeds of the gravity placed seed assures a relatively uniform germination with less loss and damage to the seed. If wet and/or muddy conditions exist at the time of planting and a seed boot plugs with mud, grass, crop or surface debris or the like, the diffuser of the invention simply keeps seed from blowing from the included vents. A warning device alerts the operator to a plugged run earlier than with other devices which permits the operator to stop and clean the plugged condition to avoid further crop spacing skips in the field being planted.